<template>
    <div class="articleIndex " >
          <!-- 导航栏 -->
    <van-nav-bar
      class="page-nav-bar"
      left-arrow
      title="黑马头条"
      @click-left="$router.back()"
    ></van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap">
      <!-- 加载中 -->
      <div class="loading-wrap"  v-if="isLoading">
        <van-loading
          color="#3296fa"
          vertical
        >加载中</van-loading>
      </div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div class="article-detail" v-else-if="article.title">
        <!-- 文章标题 -->
        <h1 class="article-title">{{article.title}}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <van-image
            class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="article.aut_photo"
          />
          <div slot="title" class="user-name">{{article.aut_name}}</div>
          <div slot="label" class="publish-date">{{article.pubdate |relativeTime}}</div>
           <FollowUser
            class="follow-btn"
            :isFollowed="article.is_followed"
            :userId ="article.aut_id"
            @update_is_followed="article.is_followed = $event"
            ></FollowUser>

        </van-cell>
        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <div 
         class="article-content markdown-body"
         v-html="article.content"
         ref="article-content"
         ></div>
        <van-divider>正文结束</van-divider>
        <CommentList 
        :source="article.art_id"
        @onload-success="totalCommentCount = $event.total_count"
        :list="commentList"
        @reply-click='onReplyClick'
        ></CommentList>

            <!-- 底部区域 -->
          <div class="article-bottom">
            <van-button
              class="comment-btn"
              type="default"
              round
              size="small"
              @click="isPostShow = true"
            >写评论</van-button>
            <van-icon
              name="comment-o"
              badge="123"
              color="#777"
            />
            <CollectArticle class="btn-item" 
            v-model="article.is_collected"
            :articleId="article.art_id"
            ></CollectArticle>
            <van-icon
              color="#777"
              name="good-job-o"
            />
            <van-icon name="share" color="#777777"></van-icon>
          </div>
          <!-- 底部区域下方添加 -->
        <van-popup
            v-model="isPostShow"
            position="bottom"
        >
            <CommentPost 
            :target="article.art_id"
             @post-success="onPostSuccess"></CommentPost>
        </van-popup>
      </div>
      <!-- /加载完成-文章详情 -->

      <!-- 加载失败：404 -->
      <div class="error-wrap"  v-else-if="errStatus === 404">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除！</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div class="error-wrap" v-else>
        <van-icon name="failure" />
        <p class="text">内容加载失败！</p>
        <van-button class="retry-btn">点击重试</van-button>
      </div>

      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>

      <!-- 评论回复的弹层 -->
      <van-popup
            v-model="isreplyShow"
            position="bottom"
            style="height:100%">
          <CommentReply
          v-if="isreplyShow"
          :comment='currentComment'
          @close="isreplyShow = false"
          />
        </van-popup>
      <!-- /评论回复的弹层 -->

    <!-- 注意： 如果是点击事件发生，那么$event就是鼠标事件对象
		如果是键盘事件发生，那么$event就是键盘事件对象
		如果是自定义事件发生，那么$event就是$emit触发事件时的参数 -->
    </div>
</template>

<script>
// 引入获取详情数据的接口
import {getArticleById} from '@/api/article'
import CommentList from './components/comment-list.vue'
// 图片预览
import { ImagePreview } from 'vant';
// 引入关注取关组件
import FollowUser from '../../components/follow-user/index.vue'
import CollectArticle from '@/components/collect-article/index.vue'
import CommentPost from './components/comment-post.vue'
import CommentReply from './components/comment-reply.vue'
export default {
  name: 'ArticleIndex',

  // 依赖注入
  provide:function(){
    return {
        articleId:this.articleId
    }
  },
  props: {
      articleId: {//进入此界面必须传递文章id
            type: [Number, String,Object],
            required: true
    }
  },
  components: {
    FollowUser,
    CollectArticle,
    CommentList,
    CommentPost,
    CommentReply
  },
  data () {
   return {
     article:{}, // 文章详情
     isLoading: true, // 文章加载状态
     errStatus: '', // 请求异常状态
     followLoading: false,
     isPostShow: false,
     commentList: [],
     isreplyShow:false,
     currentComment:{}  // 当前点击回复的评论项

   }
  },
  computed: {},
  watch: {},
  methods: {
      async loadgetArticleById(){
         try {
            // 随机错误
            // if (Math.random() > 0.5) {
            //     return JSON.parse('error')
            // }
            this.isLoading = true
            const {data} =  await getArticleById(this.articleId)
            console.log(data);
            this.article = data.data
            // 注意：数据更新后并不会同步更新页面，所以想要获取数据更新后的页面元素，需要延时处理
              setTimeout(() => {
                this.previewImg()
              }, 0)
         }catch(err) {
             // 加载失败 404
            if (err.response && err.response.status === 404) {
                this.errStatus = 404
            }
            this.$toast('获取失败')
             console.log('获取详情信息失败',err);
         }
          // 加载完成
         this.isLoading = false

      },

      // 图片预览方法
      previewImg () {
      const contentEl = this.$refs['article-content']
      const allImg = contentEl.querySelectorAll('img')
      const images = []
      allImg.forEach((element, index) => {
        images.push(element.src)
        element.onclick = () => {
            ImagePreview({
                images,
                startPosition: index
            })
        }
    })
      },

      onPostSuccess (data) {
         // 关闭弹出层
        this.isPostShow = false
         // 将发布内容显示到列表顶部
         this.commentList.unshift(data.new_obj)
      },

      onReplyClick(comment) {
        // 从子对象内传递过来的数据
        // console.log(comment);
        this.currentComment = comment
        // 显示评论回复弹出层
        this.isreplyShow =true
      }

    
  },
  created () {
      this.loadgetArticleById()
     
  },
  mounted () {
  },
}
</script> 

<style scoped lang="less">
@import './github-markdown.css';
.articleIndex {
    .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    .van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
  /deep/ .van-icon { //这样可以让子组件文章收藏的收藏图片变大
    font-size: 40px;
  }
}
</style>